In the treatment of diseases in the lung, e.g. lung cancer, as well as diseases in other anatomical areas of a body, physical access to a diseased or normal tissue region may be a challenge. This is especially the case if the diseased region lies deep within the body of the patient. Furthermore, efficient delivery and subsequent uptake of therapeutic molecules, such as a drug or genetic compound, to an anatomical target tissue is often a problem.
Electroporation is a known method used to deliver drugs and genetic material to various biologic tissues, where the uptake of these substances into tissue cells is enhanced through the application of electric pulses of specific amplitude. The delivery of drugs by electroporation is also known as electro-chemotherapy (ECT) and the delivery of genes as Gene Electro Transfer (GET). In ECT and GET applications, electroporation is used to create a transient permeabilization of the cell membranes in a target tissue area with the purpose of enhancing the uptake of the chemotherapeutic agents as well as the uptake and expression of genetic materials.
In addition to the delivery of therapeutic molecules, electroporation has a stand-alone application that is known as irreversible electroporation (IRE). In IRE, the amplitude of electric pulses is increased beyond the levels used in ECT and EGT, which creates a permanent permeabilization of the cell membranes in a target tissue area with the purpose of promoting cell death through cell leakage. A further application is the ablation of target tissue through the use of nanosecond pulse electric fields or the stimulation of cells through the application of nanosecond or picosecond pulse electric fields.
In order to provide an efficient application of pulse electric fields two or more electrode poles have to be brought into—or into close vicinity of—the region to be treated (target region). Examples of devices used for Electroporation are known from U.S. Pat. Nos. 5,674,267 and 6,278,895. These devices consist of an array of needle-type electrodes arranged as individual electrodes inserted via some external plate-shaped element providing a fixed distance between and relative position of the individual needles. If the target region is situated in a remote region of the body, such as the deeper regions of the lung or brain, the placement of electrodes may in itself be harmful to intervening tissue through which the electrodes need to traverse in order to be located in the desired region. Furthermore, a large access area must be available, and for applications in the brain this will entail creating a large hole in the patient's skull. Therefore, it is evident that the mentioned prior art devices are only well-suited for treatment in target regions in close proximity to an outer surface of the body, because an attempt to treat deeper-lying regions would cause excessive trauma to the intervening tissue.
There is thus a need for an electroporation device and an electroporation method that overcomes the shortcomings of the presently known devices and methods.